Studies on the transfer of substances from one cell to another will be continued. These will involve the labeling of normal cell constituents with radioactive and assaying for transfer by autoradiography. Studies of the development, in tissue culture, of characteristic neuron properties will be continued. Particular emphasis will be placed on studying redevelopment of interconnections between neurons put into culture as isolated separate cells. The development of the abilities to synthesize and respond to transmitters will continue to be studied in such cultures.